JP3203634B2 - Liquid crystal alignment agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a liquid crystal aligning agent. More specifically, the present invention relates to a liquid crystal alignment agent which, when used as a liquid crystal alignment film, has excellent film thickness uniformity, good liquid crystal alignment, excellent voltage holding ratio and long-term reliability, and can provide a liquid crystal display device with a high pretilt angle. .

[0002]

2. Description of the Related Art Conventionally, a layer of nematic liquid crystal having a positive dielectric anisotropy is formed between substrates with transparent electrodes to form a sandwich structure, and the major axis of the liquid crystal molecules is 90
2. Description of the Related Art There is known a liquid crystal display device having a TN liquid crystal cell that is twisted continuously (TN liquid crystal display device). The alignment of the liquid crystal in the TN type liquid crystal display element is formed by a liquid crystal alignment film made of rubbed polyimide or the like.

[0003]

However, when a TN-type liquid crystal display device is manufactured using a conventionally known liquid crystal alignment film made of polyimide or the like, the voltage holding ratio of the liquid crystal display device is low or the long-term reliability is low. During the test, there is a problem that white stains occur in the liquid crystal cell, and display failure occurs due to a small pretilt angle of liquid crystal molecules.
The liquid crystal alignment film is usually obtained by applying a liquid crystal alignment agent composed of a resin solution on a substrate and drying the liquid crystal alignment film. There is also a problem.

An object of the present invention is to provide a novel liquid crystal aligning agent. Another object of the present invention is to provide a liquid crystal alignment film which is capable of providing a high pretilt angle liquid crystal display element having excellent film thickness uniformity, good liquid crystal alignment properties, and excellent voltage holding ratio and long-term reliability. It is to provide an alignment agent.
Still other objects and advantages of the present invention will become apparent from the following description.

[0005]

According to the present invention, the above objects and advantages of the present invention are as follows: (A) The following general formula (1)

[0006]

Embedded image

(Wherein R ¹ is a tetravalent organic group in the formula (1)) (hereinafter referred to as “compound (I)”); The following general formula (2)

[0008]

Embedded image

(Wherein R ² is an alkyl group, an alkoxyl group or a halogen atom, and a is an integer of 0 to 4) (hereinafter referred to as “compound (II)”). (Ii) the following general formula (3):
(4), (5), (6) and (7)

[0010]

Embedded image

In the formulas (3) to (7), R ³ , R ⁴ , R ⁵ ,
R ⁶ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² and R ¹³ are each independently an alkyl group, an alkoxyl group or a halogen atom; R ⁷ is a divalent organic group; c, h, i
And j are each independently an integer from 0 to 3;
e, f, g, and k are each independently an integer of 0 to 4), and at least one aromatic diamine selected from the group of compounds represented by the following formula (hereinafter, referred to as “compound (III)”): (Iii) the following general formula (12)

Embedded image (In the general formula (12), R ²³ and R ²⁴ are each independently:
An alkyl group, an alkoxyl group or a halogen atom
R ²⁵ and R ²⁶ are each independently a divalent organic group
R ²⁷ is a divalent organic group having a steroid skeleton.
And r and s are each independently an integer from 0 to 4)
Diamine having a steroid skeleton represented by (hereinafter, referred to as
(Hereinafter referred to as "specific polymer (I)") and imidation formed by subjecting the specific polymer (I) to dehydration and ring closure. This is achieved by a liquid crystal alignment agent characterized by containing at least one of polymers (hereinafter, referred to as “specific polymer (II)”).

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in detail, which will clarify the objects, configurations, advantages and effects of the present invention.

The liquid crystal aligning agent of the present invention contains the specific polymer (I) and / or the specific polymer (II).

<Compound (I)> In the compound (I) used in the present invention, R ¹ is a tetravalent organic group, preferably an organic group having 4 to 12 carbon atoms.

As a specific example of R ¹ , the following general formula (9-
1) and (9-2)

[0016]

Embedded image

(In the general formula (9-1), R ¹⁵ , R ¹⁶ , R ¹⁷
And R ¹⁸ each independently represent a hydrogen atom or
And m, n and o each independently represent an integer of 0 or 1, and when m, n or o is 0, (CH ₂ ) _m , (CH ₂ ) _n or (CH ₂ ) _o represents a single bond. In Formula (9-2), R ¹⁹ represents an alkyl group, an alkoxyl group, or a halogen atom, and p represents an integer of 0 to 4. )). Among them, a tetravalent organic group represented by the general formula (9-1) is preferable.

The compound (I) having an organic group represented by the general formula (9-1) includes, for example, 1,2,3,4-
Cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3 , 5-tricarboxycyclopentylacetic acid dianhydride.

As the compound (I) having an organic group represented by the general formula (9-2), for example, 3,4-
Dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic anhydride, 3,4-dicarboxy-6-methyl-1,2,3,4-tetrahydro-1-naphthalene succinic anhydride, 3,4-dicarboxy-7-methyl-1,
2,3,4-tetrahydro-1-naphthalene succinic anhydride and the like can be mentioned.

Further, other compounds (I) include:
For example, butanetetracarboxylic dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 2,3,
4,5-tetrahydrofurantetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofural) -3
-Methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2,2,2] -oct-7-ene-
Aliphatic dianhydride or alicyclic dianhydride such as 2,3,5,6-tetracarboxylic dianhydride;

Pyromellitic dianhydride, 3,3 ', 4,4'
-Benzophenonetetracarboxylic dianhydride, 3,3 ',
4,4'-biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ' , 4,4'-biphenylethertetracarboxylic dianhydride, 3,3 ', 4,4'-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3', 4,4'-tetraphenylsilanetetracarboxylic Acid dianhydride, 1,2,
3,4-furantetracarboxylic dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenyl sulfone Dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ', 4,4'-perfluoroisopropylidene diphthalic dianhydride, 3,3' , 4,4'-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-
Bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4'-diphenyl ether dianhydride, bis (triphenylphthalic acid) A) Aromatic tetracarboxylic dianhydride such as -4,4'-diphenylmethane dianhydride.

Of these, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,
2,3,4-cyclobutanetetracarboxylic dianhydride,
1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1- Naphthalene succinic anhydride, 3,4-dicarboxy-6-methyl-1,2,3,4-tetrahydro-1-
Naphthalene succinic anhydride, 3,4-dicarboxy-7
-Methyl-1,2,3,4-tetrahydro-1-naphthalenesuccinic anhydride, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2
-Dicarboxylic dianhydride and bicyclo [2,2,2]-
Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride is preferred, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 2,3,5-tricarboxycyclopentyl acetic acid dianhydride are preferred. Anhydrides are particularly preferred. These are 1
These can be used alone or in combination of two or more.

<Compound (II)> Regarding R ^{2 in the} above formula (2) relating to compound (II) used in the present invention, (a) the alkyl group is preferably an alkyl group having 1 to 6 carbon atoms, Alkyl groups of formulas 1 to 3 are more preferred. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, n-hexyl,
Examples thereof include a cyclohexyl group, and the (b) alkoxyl group is preferably an alkoxyl group having 1 to 6 carbon atoms, more preferably an alkoxyl group having 1 to 3 carbon atoms. Specific examples include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, t-butoxy, n-pentoxy, n-
Examples include a hexyloxy group and a cyclohexyloxy group. Examples of the halogen atom (c) include chlorine, fluorine, bromine, and iodine, and chlorine and fluorine are preferred.

As the compound (II), for example, 1,2-phenylenediamine, 3-methyl-1,2-phenylenediamine, 4-methyl-1,2-phenylenediamine, 4,5-dimethyl-1,2 -Phenylenediamine,
3-ethyl-1,2-phenylenediamine, 3-methyl-1,2-phenylenediamine, 4-ethyl-1,2-phenylenediamine, 4,5-diethyl-1,2-phenylenediamine, 3-methoxy- 1,2-phenylenediamine, 4-methoxy-1,2-phenylenediamine, 4.5
-Dimethoxy-1,2-phenylenediamine, 3-ethoxy-1,2-phenylenediamine, 4-ethoxy-1,
2-phenylenediamine, 3-chloro-1,2-phenylenediamine, 4-chloro-1,2-phenylenediamine, 3-fluoro-1,2-phenylenediamine, 4-
Fluoro-1,2-phenylenediamine, 1,3-phenylenediamine, 2-methyl-1,3-phenylenediamine, 4-methyl-1,3-phenylenediamine,

5-methyl-1,3-phenylenediamine, 2-ethyl-1,3-phenylenediamine, 4-ethyl-1,3-phenylenediamine, 5-ethyl-1,3
-Phenylenediamine, 2-methoxy-1,3-phenylenediamine, 4-methoxy-1,3-phenylenediamine, 5-methoxy-1,3-phenylenediamine, 4
-Ethoxy-1,3-phenylenediamine, 5-ethoxy-1,3-phenylenediamine, 4-chloro-1,3-
Phenylenediamine, 5-chloro-1,3-phenylenediamine, 4-fluoro-1,3-phenylenediamine, 5-fluoro-1,3-phenylenediamine, 1,4
-Phenylenediamine, 2-methyl-1,4-phenylenediamine, 2,3-dimethyl-1,4-phenylenediamine, 2,5-dimethyl-1,4-phenylenediamine,
2,6-dimethyl-1,4-phenylenediamine, 2,3
-Diethyl-1,4-phenylenediamine, 2,5-diethyl-1,4-phenylenediamine, 2,6-ethyl-
1,4-phenylenediamine, 2-methoxy-1,4-phenylenediamine, 2-ethoxy-1,4-phenylenediamine, 2-chloro-1,4-phenylenediamine,
2,3-dichloro-1,4-phenylenediamine, 2,5
-Dichloro-1,4-phenylenediamine, 2,6-dichloro-1,4-phenylenediamine, 2-fluoro-1,
4-phenylenediamine, 2,3-difluoro-1,4-
Phenylenediamine, 2,5-difluoro-1,4-phenylenediamine, 2,6-difluoro-1,4-phenylenediamine and the like. Of these, 1,2-phenylenediamine, 1,3-phenylenediamine, 1,4
-Phenylenediamine, 2-methyl-1,4-phenylenediamine, 2-ethyl-1,4-phenylenediamine, 2-methoxy-1,4-phenylenediamine, 2-
Ethoxy-1,4-phenylenediamine, 2-chloro-
1,4-phenylenediamine and 2-fluoro-1,4
-Phenylenediamine is preferred, and 1,3-phenylenediamine and 1,4-phenylenediamine are particularly preferred. These can be used alone or in combination of two or more.

<Compound (III)> used in the present invention
Compounds of the above general formulas (3) to (7) for compound (III)
R ^Three~ R⁶And R⁸~ R¹³Is an alkyl group, alkoxyl
Group or a halogen atom, R^TwoA
Description of alkyl group, alkoxyl group and halogen atom
It should be applied as it is including preferred embodiments and specific examples.
Can be. Further, R in the general formula (5)⁷Is a divalent organic group
And specifically, the following formulas (10-1) to (10-12)

[0027]

Embedded image

The divalent group represented by

As a specific example of the compound represented by the general formula (3), 1,5-diaminonaphthalene is preferable. Specific examples of the compound represented by the general formula (4) include 3,3′-dimethyl-4,4′-diaminobiphenyl, 2,2 ′, 5,5′-tetrachloro-4,
4'-diaminobiphenyl, 2,2'-dichloro-4,4 '
-Diamino-5,5'-dimethoxybiphenyl, 3,3'-
Dimethoxy-4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl and the like are preferred.

Specific examples of the compound represented by the general formula (5) include 4,4'-diaminodiphenylmethane,
4'-diaminodiphenyl ether, 9,9-bis (4-
Aminophenyl) fluorene, 4,4 '-(p-phenyleneisopropylidene) bisaniline, 4,4'-(m-phenyleneisopropylidene) bisaniline, 2,2-bis [4- (4-aminophenoxy) phenyl] propane 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenylsulfone, 4,4′-diaminodiphenylsulfide, 4,4′-diaminobenzanilide, 3,4 ′
-Diaminodiphenyl ether, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4 '
-Diaminobenzophenone, 2,2-bis [4- (4-
Aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4- Aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl)-
10-hydroanthracene, 4,4'-methylene-bis (2-chloroaniline), 2,2'-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl]
Hexafluoropropane, 4,4′-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl and the like are preferred.

As a specific example of the compound represented by the general formula (6), 2,7-diaminofluorene is preferable. Specific examples of the compound represented by the general formula (7) include 5-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane and 6-amino-1- (4′-amino And phenyl) -1,3,3-trimethylindane. Among the compounds represented by these general formulas (3) to (7),
The compound represented by formula (5), (6) or (7) is more preferred.

Then, among the compounds represented by the above general formulas (5), (6) and (7), 4,4'-diaminodiphenylmethane, 1,5-diaminonaphthalene, 4,4'-
Diaminodiphenyl ether, 2,7-diaminofluorene, 9,9-bis (4-aminophenyl) fluorene, 4,4 '-(p-phenyleneisopropylidene) bisaniline, 4,4'-(m-phenyleneisopropylidene) bisaniline 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 5-amino-1-
(4'-aminophenyl) -1,3,3-trimethylindane and 6-amino-1- (4'-aminophenyl)
-1,3,3-Trimethylindane is preferred. These can be used alone or in combination of two or more.

<Compound (IV)> The compound (IV) used in the present invention has the following general formula (1)
It is a diamine having a steroid skeleton represented by 2) .

[0034]

Embedded image

(In the general formula (12), R ²³ and R ²⁴ are
Each independently represents an alkyl group, an alkoxyl group or a halogeno group;
R ²⁵ and R ²⁶ are each independently divalent
R ²⁷ is a divalent organic compound having a steroid skeleton
And r and s are each independently an integer from 0 to 4
is there). Preferred examples of the following formulas (17) to (19)

[0036]

[0037]

Embedded image

The compounds represented by the formulas (17) and (19) are particularly preferable. These can be used alone or in combination of two or more.

In producing the specific polymer (I) used in the present invention, the compound (II) is used in an amount of 10 to 70 mol% based on all diamines, and the compound (III) is used in an amount of 30 to 80 mol% based on all diamines. The mole ratio of the compound (IV) is preferably 0.5 to 25 mole% of the total diamine. If the use ratio of the compound (II) is less than 10 mol%, it is difficult to obtain a sufficiently high voltage holding ratio, and if it exceeds 70 mol%, the long-term reliability of the liquid crystal display device tends to be poor. When the use ratio of the compound (III) is less than 30 mol%,
The long-term reliability of the liquid crystal display element tends to be poor, and
If it exceeds mol%, it is difficult to obtain a sufficiently high voltage holding ratio. Further, when the use ratio of the compound (IV) is less than 0.5 mol%, the obtained pretilt angle tends to be small,
If it exceeds 25 mol%, the solubility of the specific polymer in the solvent tends to decrease.

<Synthesis of Specific Polymer (I)> The specific polymer (I) constituting the liquid crystal aligning agent of the present invention is obtained by mixing the tetracarboxylic dianhydride of the compound (I) with the compound (I)
It is synthesized by reaction with the diamine compounds of I), (III) and (IV). The ratio of the compound (I) and the total diamine compound used for the synthesis reaction of the specific polymer (I) is such that the acid anhydride group of the compound (I) is 0.2 to 2 equivalents to 1 equivalent of the amino group. Preferably, the amount is 0.3 to 1.2 equivalents.

The compound (I) and the diamine compound are preferably reacted in an organic solvent at a reaction temperature of 0 to 100 ° C. for 1 to 48 hours.

The organic solvent is not particularly limited as long as it can dissolve the polyamic acid produced by the reaction. Aprotic polar solvents such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide; m-cresol And phenolic solvents such as xylenol, phenol and halogenated phenol.

It is to be noted that alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons, which are poor solvents, are used in combination with the above organic solvent to such an extent that the resulting polymer does not precipitate. be able to. Examples of such poor solvents include methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. , Methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether,
Ethylene glycol i-propyl ether, ethylene glycol n-butyl ether, ethylene glycol n-hexyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol Monobutyl ether,
Diethylene glycol monomethyl ether acetate,
Diethylene glycol monoethyl ether acetate,
Ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol-n-propyl ether acetate, ethylene glycol-i-propyl ether acetate, ethylene glycol-n-butyl ether acetate, ethylene glycol-n-hexyl ether acetate, 4-hydroxy -4-methyl-2-pentanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2-hydroxy- Methyl 3-methylbutanoate, 3
-Methyl methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o -Dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene and the like. These can be used alone or in combination of two or more.

The amount of the organic solvent used is preferably such that the total amount of compound (I) and all diamine compounds is 0.1 to 30% by weight based on the total amount of the reaction solution.

Further, at the time of synthesis of the specific polymer (I), terminal modification prepared by adding an acid anhydride having only one anhydride group or a monoamine compound for the purpose of controlling molecular weight, improving coatability on a substrate, and the like. The specific polymer (I) of the type and the specific polymer (II) obtained by dehydrating and cyclizing the same can be used in the present invention without any problem.

Examples of the acid anhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, and n-tetradecyl succinic anhydride. , N-hexadecyl succinic anhydride, n-octadecyl succinic anhydride and the like.

Examples of the above monoamine include aniline, cyclohexylamine, n-butylamine, n-butylamine and the like.
-Pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-
Decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n- Eicosylamine and the like can be mentioned.

<Specific Polymer (II)> The specific polymer (II) constituting the liquid crystal aligning agent of the present invention is the specific polymer (I)
Can be obtained by heating or by dehydration and ring closure in the presence of a dehydrating agent and a dehydration ring closure catalyst. This specific polymer (II) is usually a polyimide or a polyisoimide. The reaction temperature in the case of dehydration ring closure by heating is preferably 60 to 250 ° C, more preferably 100 to 250 ° C.
１７０170 ° C.

Further, the reaction for the dehydration ring closure in the presence of a dehydrating agent and a dehydration ring closure catalyst can be carried out in the above-mentioned organic solvent. The reaction temperature is usually 0 to 180 ° C, preferably 60 to 150 ° C. Acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used as the dehydrating agent. Examples of the dehydration ring-closing catalyst include, but are not limited to, tertiary amines such as pyridine, collidine, lutidine, and triethylamine. The amount of the dehydrating agent used is 1.5 to 1.5 mol per repeating unit of the specific polymer (I).
Preferably, it is 20 mol. The amount of the dehydration ring-closing catalyst used is preferably 0.5 to 10 mol per 1 mol of the dehydrating agent used.

<Specific polymer (I) and specific polymer (I)
Intrinsic viscosity of I)> Intrinsic viscosity of specific polymer (I) and specific polymer (II) thus obtained [ηinh =
ln (t / t0) / C, where C = 0.5 g / dl, t
Is the flow rate of the polymer solution, and t0 is the flow rate of N-methyl-2-pyrrolidone. 30 ° C, N-methyl-2-
Measured in pyrrolidone, then measured intrinsic viscosity under the same conditions]
Is usually 0.05 to 10 dl / g, preferably 0.05
５5 dl / g.

<Liquid Crystal Alignment Agent> The liquid crystal alignment agent of the present invention is used as a uniform solution in which the specific polymer (I) and / or the specific polymer (II) described above is dissolved in an organic solvent.

As the organic solvent, the specific polymer (I)
The above-mentioned aprotic solvents, phenolic solvents and the like which can be used in the production or the above-mentioned alcohols, ketones, esters, ethers and halogen hydrocarbons which can be used in the production of the specific polymer (II) with these solvents And mixed solvents with poor solvents such as hydrocarbons to such an extent that the polymer is not precipitated.

The concentration of the specific polymer (I) and / or the specific polymer (II) in the solution is usually 0.1 to 2
0% by weight, preferably 0.5 to 10% by weight.

The liquid crystal aligning agent of the present invention comprises a specific polymer (I)
For the purpose of further improving the adhesion between the specific polymer (II) and the substrate, a functional silane-containing compound shown below may be contained.

Examples of the functional silane-containing compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2- Aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-
Aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N- Triethoxysilylpropyltriethylenetriamine, N-
Trimethoxysilylpropyltriethylenetriamine,
10-trimethoxyisyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl- 3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3 -Aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, and the like.

<Production of Liquid Crystal Display Element> A liquid crystal display element obtained by using the liquid crystal aligning agent of the present invention can be produced, for example, by the following method.

(1) The liquid crystal aligning agent of the present invention is applied to the transparent conductive film side of the substrate provided with the patterned transparent conductive film by a roll coater method, a spinner method, a printing method, or the like. The coating is preferably formed by heating at a temperature of 120 to 200 ° C. The thickness of this coating film is usually 0.001 to 1 μm, preferably 0.005 to 0.5.
μm. The liquid crystal aligning agent of the present invention containing the specific polymer (I) forms a coating film to be a liquid crystal alignment film by removing an organic solvent after coating, and is further heated to form an imidized coating film. It can also be a membrane. The formed coating film is subjected to a rubbing process of rubbing in a certain direction with a roll wrapped with a cloth made of synthetic fibers such as nylon and rayon, whereby the alignment ability of liquid crystal molecules is imparted to the coating film and becomes a liquid crystal alignment film. .

As the substrate, for example, a transparent substrate made of glass such as float glass or soda glass; or a plastic film such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, or polycarbonate can be used. As the transparent conductive film, NESA film made of SnO2, In ₂ O ₃ -
An ITO film or the like made of SnO ₂ can be used, and a photo-etching method, a method using a mask in advance, or the like is used for patterning these transparent conductive films. When applying the liquid crystal alignment agent, a functional silane-containing compound, titanate, or the like may be applied on the substrate and the transparent conductive film in advance to further improve the adhesion between the substrate and the transparent conductive film. it can.

(2) Two substrates on each of which a liquid crystal alignment film is formed as described above are prepared, and the two substrates are separated by a gap (cell gap) such that the rubbing directions of the respective liquid crystal alignment films are orthogonal or antiparallel. The periphery of the substrate is sealed with a sealant, filled with liquid crystal, and the filling hole is sealed to form a liquid crystal cell. A liquid crystal display device is obtained by laminating a polarizing plate on the outer surface of the liquid crystal cell such that the polarization direction matches or is orthogonal to the rubbing direction of the liquid crystal alignment film of the substrate.

As the sealing agent, for example, an epoxy resin containing a hardening agent and aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal. Among them, a liquid crystal that forms a nematic liquid crystal is preferable.
Azoxy liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal,
Biphenylcyclohexane liquid crystal, pyrimidine liquid crystal,
Dioxane-based liquid crystals, bicyclooctane-based liquid crystals, cubane-based liquid crystals, and the like are used. In addition, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate and cholesteryl carbonate, and chiral agents sold under the trade names C-15 and CB-15 (Merck Ltd.) are added to these liquid crystals. Can also be used. Further, p-decyloxybenzylidene-p-
Ferroelectric liquid crystals such as amino-2-methylbutylcinnamate can also be used.

As the polarizing plate used on the outer surface of the liquid crystal cell, a polarizing plate in which a polarizing film called an H film in which polyvinyl alcohol is stretched and oriented and iodine is absorbed by a cellulose acetate protective film or an H film is used. And a polarizing plate composed of the same.

[0062]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. For each liquid crystal display device manufactured by the following examples and comparative examples, the liquid crystal alignment of the liquid crystal display device, the voltage holding ratio of the liquid crystal display device, the reliability of the liquid crystal display device, the pretilt angle of the liquid crystal display device, the liquid crystal The thickness uniformity of the alignment film was evaluated. The evaluation method is as follows.

[Liquid Crystal Alignment of Liquid Crystal Display Element] The presence or absence of abnormal domains in the liquid crystal display element when the liquid crystal display element was turned on / off was observed with a polarizing microscope. . [Voltage holding ratio of liquid crystal display element] Evaluation was made by turning off the voltage of 5 V applied to the liquid crystal display element and measuring the voltage holding ratio after 16.7 msec. [Reliability of Liquid Crystal Display Element] The liquid crystal display element was driven in a constant temperature / humidity chamber at a temperature of 80 ° C. and a humidity of 80% with a rectangular wave of 5 V and 60 Hz for 1000 hours.

[Pretilt Angle of Liquid Crystal Display Element] [TJSc
hffer et al., J. Appl. Phys., 19, 2013 (1980)]. [Thickness uniformity of liquid crystal alignment film] A liquid crystal alignment agent is applied on a silicon wafer by printing, the substrate is baked at 180 ° C. for 1 hour, ten measurement points are selected, the film thickness is measured, and the average of the ten points is averaged. The average film thickness was obtained, and the difference between the maximum film thickness and the minimum film thickness was obtained as film thickness unevenness.

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

Synthesis Example 1 2,3,5-Tricarboxycyclopentylacetic acid dianhydride
44.83 g (0.20 mol), 1.41 g (0.05 mol) of 1,4-phenylenediamine, 27.76 g (0.14 mol) of 4,4'-diaminodiphenylmethane and the compound of the above formula (17) 6.43 g (0.01 mol) and N- meth
Dissolved in 749 g of tyl-2-pyrrolidone and left at room temperature for 6 hours
Reaction. The reaction mixture is then flushed with a large excess of methanol.
And the reaction product was precipitated. And then Methanow
And dried under reduced pressure at 40 ° C. for 15 hours to obtain a specific polymer (Ih). Further, the specific polymer (Ih) 4
0.0 g to 800 g of N-methyl-2-pyrrolidone,
110 in 35.5 g of pyridine and 27.5 g of acetic anhydride
Imidization for 4 hours at a temperature of 0.91 dl / g
37.0 g of the specified polymer (IIh) was obtained.

Synthetic Example 2 In Synthetic Example 1, diamine was converted to 1,4-phenylenediamine (5.41 g, 0.05 mol), 4,4′-diaminodiphenylmethane (27.76 g, 0.14 mol) and the compound represented by the formula (19) )) To obtain a specific polymer (Ii) in the same manner as in Synthesis Example 1 except that 7.40 g (0.01 mol) of the compound was used, and further using this specific polymer (Ii) in the same manner as in Synthesis Example 1. To obtain 37.0 g of the specific polymer (IIi) having an intrinsic viscosity of 0.81 dl / g.

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

Example 1 5 g of the specific polymer (IIh) obtained in Synthesis Example 1 was dissolved in γ-butyrolactone to obtain a solution having a solid content of 4% by weight, and this solution was filtered through a filter having a pore size of 1 μm to obtain a liquid crystal. An alignment agent solution was prepared. This solution was applied on a transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film using a printing machine for applying a liquid crystal aligning agent, and dried at 180 ° C. for 1 hour. Was formed. A rubbing machine having a roll in which a rayon cloth was wound around the coating film was subjected to a rubbing treatment at a roll rotation speed of 500 rpm and a stage moving speed of 1 cm / sec.

Two substrates on which the liquid crystal alignment film was formed as described above were prepared, and the outer edge of each substrate was formed with a diameter of 17 mm.
After applying an epoxy resin adhesive containing aluminum oxide spheres having a thickness of μm by screen printing, the gap between the two substrates is set so that the liquid crystal alignment film surfaces of the respective substrates face each other and the rubbing directions of the liquid crystal alignment films are orthogonal to each other. , And the outer edge portion was press-bonded to cure the adhesive. Next, a nematic liquid crystal (Me
After filling with rck Ltd., ZLI-5081), the liquid crystal injection port is sealed with an epoxy-based adhesive, and a polarizing plate is provided on both outer surfaces of the substrate. The liquid crystal display device was manufactured by laminating so as to match the rubbing direction.

The liquid crystal display device manufactured as described above had no abnormal domains in the liquid crystal display device when the voltage was turned on and off, and had excellent liquid crystal alignment. Also, the voltage holding ratio of the liquid crystal display device was measured and found to be as high as 99.1% . Also, 1000
No white spots appeared on the liquid crystal display element in the reliability test after the lapse of time. When the pretilt angle of the liquid crystal display element was measured, it was a high value of 5.3 ° . Further, the average film thickness of the liquid crystal alignment film was 520 ° and the coating unevenness was 25 ° , and a uniform film thickness was obtained. Table 1 shows the results.

Example 2 A liquid crystal display device was produced in the same manner as in Example 1 except that a liquid crystal aligning agent was prepared using the specific polymer (IIi) obtained in Synthesis Example 2 . Liquid crystal alignment of the liquid crystal display device, the voltage holding ratio was evaluated thickness uniformity of reliability and the pretilt angle and a liquid crystal alignment film. Table 1 shows the results.

[0093]

[0094]

[Table 1]

[0095]

According to the liquid crystal alignment agent of the present invention, when a liquid crystal alignment film is formed, the liquid crystal display element has excellent film thickness uniformity, good liquid crystal alignment, and excellent voltage holding ratio and long-term reliability. Is obtained. Further, a liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention may be provided with, for example,
JP-A-222366 and JP-A-6-281937, a process of changing the pretilt angle by irradiating ultraviolet rays, or Japanese Patent Application Laid-Open No. H05-281937.
A resist film is partially formed on the surface of a liquid crystal alignment film that has been subjected to a rubbing treatment as disclosed in JP-A-10-75444, and a rubbing treatment is performed in a direction different from the previous rubbing treatment, and then the resist film is removed. By performing a process for changing the alignment ability of the liquid crystal alignment film, the visibility characteristics of the liquid crystal display element can be improved.

The liquid crystal display device having a liquid crystal alignment film formed by using the liquid crystal alignment agent of the present invention can be suitably used for a TN type liquid crystal display device, and can also be used by selecting a liquid crystal to be used to obtain an STN (Super twisted). nematic) type, SH (S
It can also be suitably used for upper homeotropic), ferroelectric and antiferroelectric liquid crystal display devices. Further, a liquid crystal display device having a liquid crystal alignment film formed using the liquid crystal alignment agent of the present invention can be effectively used for various devices,
For example, it is used for a display device such as a desk calculator, a wristwatch, a clock, a coefficient display board, a word processor, a personal computer, and a liquid crystal television.

The preferred embodiments of the present invention described in detail above will be described below. 1. Compound (I) occupying in the total diamine used for producing polyamic acid by reacting with compound (I)
A liquid crystal aligning agent in which the ratio of I) is 10 to 70 mol%, the ratio of compound (III) is 30 to 80 mol%, and the ratio of compound (IV) is 0.5 to 25 mol%. 2. Compound (I) in the total diamine used to form polyamic acid by reacting with compound (I)
A liquid crystal aligning agent wherein the ratio of I) is 10 to 60 mol%. 3. Compound (I) occupying in the total diamine used for producing polyamic acid by reacting with compound (I)
A liquid crystal aligning agent wherein the proportion of II) is from 40 to 80 mol%. 4. Compound (I) occupying in the total diamine used for producing polyamic acid by reacting with compound (I)
A liquid crystal aligning agent having a ratio of V) of 1 to 15 mol%. 5. Compound (III) is 4,4'-diaminodiphenylmethane, 1,5-diaminonaphthalene, 4,4'-diaminodiphenyl ether, 2,7-diaminofluorene, 9,
9-bis (4-aminophenyl) fluorene, 4,4-
(P-phenyleneisoprilopylidene) bisaniline,
4,4 ′-(m-phenyleneisopropylidene) bisaniline, 2,2-bis [4- (4-aminophenoxy) phenyl] propane and 5-amino-1- (4′-aminophenyl) -1,3, A liquid crystal aligning agent which is at least one kind of diamine compound selected from 3-trimethylindane. 6. A liquid crystal aligning agent wherein R ^{1 in the} formula (1) is at least one of the tetravalent groups represented by the formulas (9-1) and (9-2). 7. Compound (I) is 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 3,4-dicarboxy-1,2,3,
A liquid crystal aligning agent which is at least one of 4-tetrahydro-1-naphthalene succinic dianhydride and 2,3,5-tricarboxycyclopentyl acetic dianhydride. 8. A liquid crystal aligning agent wherein the compound (II) is 1,4-phenylenediamine.

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasuo Matsuki 2--11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) References JP-A-4-281427 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1337

Claims (1)

(57) [Claims] (A) The following general formula (1): (Wherein, R ¹ is a tetravalent organic group in the formula (1)); and (B) (i) a general formula (2) shown below. (In the formula (2), R ² is an alkyl group, an alkoxyl group or a halogen atom, and a is an integer of 0 to 4). (Ii) The following general formulas (3) and (4) ), (5), (6) and (7) (In the general formulas (3) to (7), R ³ , R ⁴ , R ⁵ , R ⁶ ,
R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² and R ¹³ are each independently an alkyl group, an alkoxyl group or a halogen atom, R ⁷ is a divalent organic group, b, c, h , I and j are each independently an integer from 0 to 3, and d, e, f,
g and k are each independently an integer of 0 to 4), and at least one aromatic diamine selected from the group consisting of compounds represented by the following general formula (12) : (In the general formula (12), R ²³ and R ²⁴ are each independently:
An alkyl group, an alkoxyl group or a halogen atom
R ²⁵ and R ²⁶ are each independently a divalent organic group
R ²⁷ is a divalent organic group having a steroid skeleton.
And r and s are each independently an integer from 0 to 4)
A liquid crystal aligning agent comprising at least one of a polyamic acid produced by reacting a diamine having a steroid skeleton represented by formula (I) and an imidized polymer produced by subjecting the polyamic acid to dehydration and ring closure.